This project consists of four related areas of investigation, all concerned with the analysis of mechanisms of attention. Special emphasis is placed on the use of lesion and/or biochemical techniques to elucidate mechanisms involved in visual attention. The four areas are: 1. attention and cerebral mechanisms of visual behavior; 2. pharmacological mechanisms of attention; 3. brain activity in attention: local cerebral glucose metabolism in sleep; and 4. the design of a general attention task.